Rio Tinto Ltd. (RTP) Iron Ore Chief Executive Sam Walsh said Friday that the company's proposed production joint venture with BHP Billiton Ltd. (BHP) won't reduce competition in the iron ore market.

"We have heard concerns that this joint venture will have a negative impact on the competition," Walsh said in a speech to a Committee for Economic Development of Australia function.

"My simple response is to say no, it will not reduce competition."

Rio Tinto and BHP are committed to have the joint venture in place by the middle of 2010, Walsh said.

Turning to the iron ore market, Walsh said mining companies need to be cautious about the recent price rally for iron ore, given that spot prices have eased to around US$80 per ton from more than US$100 per ton early last month.

The price fall mirrors recent declines in Chinese steel prices, Walsh said.

Despite his caution on the market, Walsh said that economic stimulus interventions by many governments have helped the steel and iron ore markets increase production.

Almost all of the Group of 20 countries agreed to some type of fiscal stimulus plan totaling some US$690 billion for 2009, he said.

-By Stephen Bell, contributing to Dow Jones Newswires; 61-8-9244-4243; sgbell@bigpond.com